Electric switch



Dec. Z3, 1947.

A. G. sElFRlED f. 2,433,163

ELECTRIC SWITCH Filed Feb. 7, 1944 Patented Dec. 23, 1947 UNITED As'ilrrr.

ELECTRIC SWITCH Anthony G.

The B. F.

scarica, Akron, ohio, assigner to Goodrich Company, New York, N. Y.,

a corporation of New York y Application February 7, 1944, Serial No. 521,305 12 Claims. (Cl. 20o- 152) The invention relates to electric' circuit breaking switches and especially to switches suitable for use in the presence of inflammable materials such, for example, as gasoline and benzine.

For protective purposes electric circuit breaking switches may be enclosed in protective casings or housings and provided with external operating handles for operating the mechanical switching means for making and breaking the circuit. Be# cause of difficulty in sealing such casings and because of arcing at the exposed make-and-break contacts of the switching mechanisms, the enclosed switches of prior constructions have not been wholly satisfactory for reliable and extended operation in a cyclical manner, especially in explosive atmospheres where safety is of paramount importance.

Principal objects of the invention are to provide for effectively making and breaking the electric circuit in a non-arcing manner; to provide for reliability and safety of operation of electric switches, especially in the presence of infiamagainst inflammable materials mable materials; to provide for relative rapidity of cyclical operation of such switches; and to provide simplicity and compactness of construction, convenience of manufacture and servicing, and effectiveness of operation.

Other objects of the-invention are to providev a switch having fluid-contact means arranged for operation by correlated quick-make and quickbreak means; to provide an improved switch, especially a. switch in which theI-contactscannot be stuck or frozen together as is possible in the y knife blade type of switch; and to provide for removing the switch as an integral unit from the enclosing casing.

These and other objects andadvantages will be apparent from the following description.

Inthe accompanying drawings which form a part of this specication and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a plan View from above of an electric switch mounted in a protective lcasing and constructed' in accord-ance with and embodying the invention, parts being broken away,

Fig. 2 is a sectional view in elevation taken along line 2--2 of Fig. 1, and

Fig. 3 is a view like Fig. 2 taken along line 3--3 of Fig. 1, parts being broken away,

Fig. 4 is a perspective view of the rocking plat-4 form unit.

In the embodiment of the invention illustrated in the drawings, a casing or housing I protects the electric switching means mounted therein and against objectionable dust or other foreign material deposits. The housing Ill may be of cast or sheet metal or other suitable stii material construction having a lower part I I and an upper part I2 which parts II and I2, when in assembled relation, may be held detachably together in substantially sealing contact along their abutting flanged margins by a plurality of screw fasteners I3, I3 extending.

through apertures in bosses I4, i4 of the flanged margin of the upper part and engaging the threaded walls of registering apertures in like bosses of the flanged margin of the lower part. The lower part Il may also be provided with attaching lugs I5, I5 for facilitating mounting the housing on a surface such, for example, as a floor by suitable fasteners (not shown) extending through apertures in such lugs.

The electric switching means within the housing I0 includes a base member 2l of suitable electrical insulating material such, for example, as

phenol-,aldehyde plastic material detachably secured to the bottom wall of the lower part II as by screw fasteners 22, 22. spaced-apart pedestals 23, 23 are positioned at the sides and intermediate the ends of the base member and may be yattached thereto as by spaced-apart screw fasteners 24, 24, the pedestals may include lubricant-impregnated bearing sleeves within aligned apertures forreceiving trunnions 25, 25 of a rocking platform or oscillating structure 26 extending between the pedestals transversely of the base member.

The rocking platform 26 comprises a central web or elongated plate element 30 including the integral trunnions 25,25 of relatively strong stiff 'material such, for example, as steel, the plate element having an aperture therethrough intermediate its ends for receiving and supporting a closed container 3|, desirably of cylindrical form. Elongated supporting elements 32, 32 of suitable electrical insulating plastic material and of substantially like form as that of the plate element are mounted at opposite sides of the plate element as by screw fasteners and may extend substantially along the extent of such plate element. The supporting elements 32, v.'42 have rounded grooves at the upper parts thereof in register with the aperture in the plate element 30 for accommodating and further supporting the closed container 3I.

The upper part of each supporting element may also have a depressed shelf-like portion 35 spaced from the plate element 30 in which shelf-like portion 35 may be provided a channel for re- Ceivins a conductor element 36 of electrically conductive metal material such, for example, as resilient brass strip material. The conductor elements 35, 35 are detachably secured in such channels as by spaced-apart screw fasteners 58a, 58h, 55e and 35d and include end portions .55 overlying the grooves in the supporting elements 52, which end portions are adapted to press in a springing manner against the closed container thereby retaining detachably the container on the rocking platform 25 despite the rocking movement of the latter.

For conducting the current from the conductor elements 35, 35, spaced-apart flexible conductors 4| 'and 42 extend between and are mounted on the base member 2| and the rocking platform 25 with open-looped reaches of the flexible conductors therebetween, as shown especially in Fig. 2, for accommodating the rocking movement of such platform. At the rocking platform, the flexible conductors 4| and 42 may be connected to the conductor elements 35 by the screw fasteners 38h and 35e, respectively. For positioning and assisting in relieving flexing strains on the flexible conductors adjacent the rocking platform, positioning elements 43 of suitable electrical insulating plastic material having spacedapart apertures may be provided and attached to the supporting elements 32 as by screw fasteners, as shown especially in Fig. 1. The flexible conductors 4| and 42 extend from the fasteners 35h and 35e downwardly through the adjacent apertures in the positioning elements, are looped beneath the latter elements, and extend upwardly through the other apertures therein, the conductors terminating desirably at apertured mounting members 41, 41 attached to the base' member 2| as by screw fasteners. The flexible conductor 4| extends through an aperture in the mounting member 41 to a terminal screw 5|. However, the flexible conductor 42 extends through the aperture in the other mounting member 41 and is secured to a strip element 52 oi suitable conductive material as by a screw fastener, which strip element; 52 extends along a channel in the base member 2| to a second terminal screw 53. Suitable lead-in connectors 48 may be attached to the terminal screws 5| and 53 and extend through suitable sealed apertures in the wall of the casing I0.

Coil springs 55, 55 of relatively short extent as compared to that of the reaches of the flexible conductors 4| and 42 may be disposed adjacent such conductors and seated within the apertures of the positioning elements 43, 43 and of the mounting members 41, 41 in a manner to maintain such reaches in' a generally parallel and spaced relation overlying the rocking platform in a condition to accommodate the rocking movement of the latter and to promote flexing in such reaches. The springs 55, 55 may also further relieve the conductors of flexing strains adjacent the positioning elements and the mounting members. It .is to be understood that the springs 55, 55 may extend continuously along and adjacent the reaches of the flexible conductors and that other means such, for example, as flat strip springs or other resilient means may be provided for so maintaining and positioning the reaches of the flexible conductors.

The oscillating or rocking movement of the oscillating structure 25 about the axis of oscillation through a small degree of angular movement, as shown especially in Figs. 1 to 3, may

be accomplished by a lever 55 at one end of the' plate element, preferably integral theiwith, the

lever including a rotatable projecting journal 51 at its end opposite the plate element for rolling engagement with a bifurcated element 55 mounted on a rotatable shaft structure 55 for pivotal movement relative to such structure. A coil spring 5|! mounted on the shaft 55 and having its respective ends engaging the bottom wall of the casing l5 and a projection on the shaft cooperates with an adjusting structure 5| on the shaft structure 55 to maintain the rocking platform 25 in the oil.'" or circuit breaking position. End portions of the shaft 55 may extend through apertures in the side walls of the casing. one end portion being retained by a collar fastener 54 and a washer 55, while a suitable footpedal or operating lever 52 may be mounted on the other end portion for rotating the shaft 55.

For making and breaking the electric circuit, the cylindrical closed container 5| includes therein electrically conductive fiowable material such,

for example, as-mercury and includes spacedapart contactor elements or end portions 55 and 55 of electrically conductive material interconnected by a joining portion 15 of electrical insulating material. The closed container 5| is disposed in the aperture of the plate element 55 such that the insulating joining portion 1I is at the element while the end portions 55 and 55 yare seated in the grooves of and supported by the insulating supporting elements '52, 52. The end portions 55, 55 of the conductor elements 55, 55 contact electrically and press against the end portions 55 and 55 thereby holding the closed container on the rocking'platform while facilitating quick removal of such container for servicing the electric switch. The spring pressing action of the conductor elements on the container prevents effectively arcing at such end portions 55 and 55.

In the operation of the electric switch the 4footpedal 52 is depressed from its oil' position rotating the-shaft structure 59 which in turn pivotally moves the bifurcated element 55 downwardly toward the bottom wall of the casing I5. This movement of the bifurcated element 55 causes the'rocking platform 25 to pivot or rock on its trunnions 25, 25, due to the rolling engagement of the element 55 with the projecting journal 51 of the lever 55 of such platform. The rocking or oscillating of the platform 25, when the footpedal 52 is depressed, inclines the closed container 3| such that the mercury therein flows from the end portion 55 across the joining portion 10 to the end portion 55 thereby completing thecircuit through the container 5| Current may then flow, for exampleffrom the connection at the terminal screw 55 through the strip ,element 52 and the flexible conductor 42 to the conductor element 55 and to and through the closed container 5|. The current then flows from the container 5| through the other conductor element 55 to and through the flexible conductor 4| tothe other terminal screw 5|. When the foot-pedal is released, it returns to its starting or off position under the action of the spring 50, and the platform pivots in the reverse direction oscillating the container 5| such that the mercury flows to the end portion 55 and is-no longer in contact with the other end portion 55 lthereby breaking the circuit through vsuch container. 'I'he arrangement is such that only slight changes in the position of the foot-pedal are required for oscillating the rocking platform sufficiently to make-and-break the circuit through the container which facilitates rapidity of operation without exposed arcins hence eliminating any fire hazard in the presence of inflammable materials.

During the oscillating movement of the oscillatins structure 26 the flexible conductors Ilr and I2 are maintained by the coil springs 55, 55 in a condition to accommodate such movement while such conductors ilex continuously and substantially uniformly along their reaches between the structure and the base member by virtue of their freely swung condition thereby promoting long and substantially service-free life of the electric switch.

Variations may be made without departing-V from the scope of the invention as it is defined in the following claims.

I claim:

,1. A switch comprising a housing, a base member including spaced-'apart pedestals having apertures mounted within said housing, an oscillating structure comprising a plate element of metal material having trunnions at the ends and an aperture intermediate said ends, said trunnions being disposed in the apertures of said pedestals for supporting said structure, spaced-apart supporting elements of insulating material at opposite sides of and carried by said plate element and a lever at one end of said plate element for oscillating said structure, saidlever including a rotatable projecting journal at its end opposite said plate element, a closed container extending through the aperture in said plate element and supported by said supporting elements, said container comprising electrically conductive flowable materialv andcontacto'r portions at said supporting elements adapted to be contacted by said flowable material when said structure is oscillated, conductor elements mounted on said supporting elements and resiliently engaging said contacter portions and holding said container, means connecting said conductor elements to an electric circuit, and means for oscillating said structure for making and breaking the circuit through said container, the oscillating means incuding a pivotally mounted bifurcated element engaging said projecting journal and spring means for maintaining said structure in the circuit breaking position, the connecting means comprising spaced-apart flexible conductors mounted on said base member and on said structure at said supporting elements with generally parallel open-looped reaches of the Vflexible conductors in upstanding positionsl therebetween and sleeves of helically wound spring wire surrounding the flexible conductors at ,and secured to said base member and said supporting elements and extending -along said conductors with the adjacent ends of the sleeves disposed beyond the base member and the `structure for main-l l taining the reaches in said upstanding positions.

2. A switch for' making and breaking an electric circuit through a closed container having electrically conductive fiowable material therein, .said switch comprising an oscillating structure for supporting and y,imparting oscillating movement to said container, said structure comprising a plate element of stili. material-having an aperture intermediate its ends for receiving said container and trunnions at said ends, spaced-apart supporting elements ofinsulating' material at opposite sides of and carried by said plate element for supporting saidcontainer, conductor means mounted Von said supporting elements for electrically engaging and detachably holding said container on said structure, and means for oscillating said structure.

A switch for making and breaking circuit through a rclosed an electric container having electrically conductive yflowable material therein, saidswitch comprising an oscillating structure for supporting and imparting oscillating movement to i `insulating material secured to said plate element at opposite sides thereof and having grooves in register with said aperture for embracing said container, spring conductor elements mounted on said supporting elements and extending across said groovesy for electrically engaging and resiliently holding said container, and a lever secured to said plate element at one of said ends for oscillating said structure.

4. A switch for making and breaking an electric circuit through a closed container having electrically conductive flowable material therein,

said switch comprising an oscillating structure for supporting and imparting oscillating movement to said container, said structure comprising a plate element of stiff material having an aperture intermediate its ends for receiving said container and trunnions at said ends, spaced-apart supporting elements of insulating material at opposite sides of and carried by said plate element for supporting said container, conductor means mounted on said supporting .elements for electrically engaging and detachably holding said container on said structure, means for connecting said conductor ymeans to the electric circuit and comprising a single open-looped reach of flexible conductor extending from said oscillating structure in upstanding position over said structure and resilient means for maintaining said reach connected to said structure in the upstanding position clear of mediate said ends for receiving saidcontainer,

bearings for said trunnions, spaced-apart sup porting elements of insulating material secured to said plate element at opposite sides thereof and having grooves in register with said aperture for embracing said container, spring conductor elements mounted on said supporting elements and extending across said grooves for electrically en gag'ing and resiliently holding said container, a lever secured to saidl plate element at oney of said ends for oscillating said structure, and means for connectingv said conductor element to an electrical circuit, the' connecting means comprising a single open-looped reach of flexible conductor extending from said oscillating structure in upstanding position over and clear of said structure and a flexible sleeve of spring wire closely coiled about said flexible conductor at said structure and terminating beyond the latter for so maintaining said ilexible conductor in said position while accommodating the oscillating movement of said structure.

6. A safety switch for extensive operation and relatively rapid frequency of making and breakamazes ing au electric circuit through a closed container having electrically conductive ilowable material therein, said switch comprising an oscillating structure including a single integral rocking platform of stiff material having a length along the axis of oscillation at least equal to the width thereof and mounting means at the ends of the platform extending outwardly therefrom along said axis for permitting oscillating movement of said structure, said platform having an opening therein intermediate said ends extending acro said axis from side to side of the structure for receiving said container, the wall of said opening being continuously annular for supporting said container and circumferentially embracing entirely about the latter, conductor means for connecting said container to an electric circuit and comprising a single open-looped reach of flexible conductor extending from said platform in upstanding position over said platform from one side of said axis to the other side thereof and means for maintaining said reach connected to said structure in the upstanding position with relation to said platform and the aforesaid relation to said axis clear of adjacent structure while accommodating oscillating movement of said oscillating structure and promoting continuity of substantially uniform flexing along said reach of said flexible conductor during said movement, and means for oscillating said platform about said axis through a small degree of angular movement for making and breaking the circuit through the container.

7. A safety switch for extensive operation and relatively rapid frequency of making and breaking an electric circuit through a closed container having electrically conductive iiowable material therein, said switch comprising an oscillating structure comprising a single integral and elongated rocking member of stiff material disposed at and extending lengthwise along the axis of oscillation of said structure, said member having a trunnion of said material integrally united with the material of said member at each end of the latter and extending outwardly therefrom along said axis of oscillation and said member having an opening therethrough intermediate the ends and extending from side to side of said member across said axis of oscillation for receiving said container therein, means for detachably mounting and holding said container on said structure and in said opening of the rocking member, means for connecting said container to an electric circuit while accommodating the oscillating movement of said structure, and means for oscillating said structure about said axis through a small degree of angular movement for making and breaking the circuit through the container.

8. A safety switch for extensive operation and relatively rapid frequency of making and breaking an electric circuit through a closed container having electrically conductive owable material therein, said switch comprising an oscillating structure comprising an elongated rocking member of stii plate material disposed at and extending lengthwise along the axis of oscillation of said structure, said member having a. trunnion of stiff material integrally united with said material of the member at each end of the latter and opposite spaced-apart relatively flat and broad sides and having a bore therethrough intermediate the ends and extending between said sides across said axis for receiving and circumferentially enclosing said container, spaced-apart supporting elements of insulating material extending along said member and carried by said member at said opposite sides, conductor elements of resilient material mounted on and extending along said supporting elements and constructed and arranged to resiliently maintain said container in said bore in a freely detachable manner and to electrically engage said container, means for connecting said conductor elements to an electrical circuit while accommodating oscillating movement of said structure, and means for oscillating said structure about said axis through a. small degree oi' angular movement for making and breaking the circuit through the container.

9. An oscillating structure for a safety switch adapted for frequently making and breaking an electric circuit through a closed container having electrically conductive liquid material therein, said structure comprising an elongated rocking member of stiif plate material for disposition at and lengthwise along the axis of oscillation, said member having trunnions of stiff material integrally united therewith and extending outwardly from the ends of said member at and along said axis and said member having a bore therethrough intermediate said ends and extending between opposite sides of said member in the direction -across said axis for receiving said container therein, spaced-apart supporting elements of insulating material at said sides and carried by said member, and means including conductor means for holding said container in a freely detachable manner on said structure in said bore and for connecting said container to an electric circuit.

10. An oscillating structure for a safety switch adapted for frequently making and breaking an electric circuit through an elongated closed container having electrically conductive liquid material therein and contactar elements at its ends, said structure comprising an elongated rocking member of stii metal plate material for disposition at and lengthwise along the axis of oscillation, said member having trunnions of said material integrally united therewith and extending outwardly from the ends of said member at and along said axis therethrough intermediate the depth thereof and said ends and extending between opposite sides of said member in the direction across said axis for receiving said container therein, the wall of said bore extending entirely about the circumferential extent of said container, spaced-apart supporting elements of insulating material at and extending along said sides and carried by said member, said elements having openings therethrough in register with said bore providing walls of said insulating material for supporting said container at said contactor elements, and means including conductor elements of resilient metal material mounted on and extending along said supporting elements for electrically engaging said contacter elements and connecting said container to an electric circuit, said conductor elements being constructed and arranged to hold said container in a freely detachable manner in said bore of said member and said openings in said supporting elements.

11. A switch comprising a base member, a platform mounted on said base member for rocking movement about an axis, means on said platform for making and breaking an electric circuit under the rocking movement, a pair of flexible conductors axially spaced-apart and mounted on said base member at opposite sides of said axis, each conductor extending in a loop across the and said member having a, bore platform to a position thereon at the opposite side of said axis in crossed relation-with the other loop so that the influence of one oi said conductors in aiiecting the rocking movement ofsaid platform tends ,to counteract the influence oi the other conductor under the rocking movement, and means for rocking said platform for making and breaking the circuit through the iirst said means.

12. A switch comprising a base, an elongated platform mounted on said base member for rocking movement about an axis and extending lengthwise along said axis, contact means including conductor elements on said platform spacedapart transversely of said axis for making and breaking an electric circuit under the rocking movement, a pair of flexible conductors mounted on said base member at opposite sides of said axis, each conduotor extending in a loop in upstanding position with relation to said platform to a position on theiatter at the opposite side of said axis in crossed relation with the other loop so that the influence o! one o! said conductors in aflecting the rocking movement oi said platform tends to counteract the iniuence of the other conductor under the rocking movement, and means for rocking said ing the circuit throughsaid contact means.

ANTHONY G. SEIFRIED.

REFERENCES CITED The following references are ci record in the file oi this patent:

UNITED STATES PATENTS platform for making and breaki 

